Unit Converter
Convert length, weight, temperature, area, and volume instantly.
About unit systems
Most of the world uses the International System of Units (SI): meters, kilograms, Celsius. The United States still relies heavily on the imperial system (inches, feet, miles, pounds, Fahrenheit), which means conversions come up constantly in international shopping, recipes, technical specs, and travel.
Length, weight, area, and volume conversions use fixed multiplication factors between units. Temperature is different: it requires a formula (°F = °C × 9/5 + 32) because Celsius, Fahrenheit, and Kelvin start their scales at different zero points.
Frequently asked questions
Why is temperature conversion different from the others?
Length, weight, area, and volume are linear conversions (multiply by a fixed factor). Temperature scales have different reference points — 0°C equals 32°F, not 0°F — so the formula needs addition, not just multiplication.
What is the difference between pounds and kilograms?
The pound (lb) is the imperial unit of mass, used mainly in the US. 1 pound equals approximately 0.4536 kilograms. The kilogram (kg) is the SI standard unit, used across most of the world.
Does this tool convert cooking measurements like cups?
This calculator focuses on standard physical units (length, weight, temperature, area, volume). Cooking measurements vary by ingredient density and have no exact universal conversion.